Carboxylic acids are industrially useful chemicals used both as end-products and as starting materials in a variety of different processes. Examples of dicarboxylic acids include glutaric acid, a common precursor for plasticers and polyesters. Also suberic acid (hexane-1,6-dicarboxylic acid) and adipic acids are useful precursors for different chemicals, such as polyamide resins or nylon 6-6.
Adipic acid (1,6-hexanedioic acid) is an organic compound with the formula (CH2)4(COOH)2. From an industrial perspective, it is the most important dicarboxylic acid. About 2.5 billion kilograms of adipic acid is produced annually; the main use for adipic acid is as a precursor for the production of nylon.
R. Noyori and co-workers, Science, 281, 1646-1647 (1998), discloses that adipic acid may be produced from the oxidation of cyclohexanol or cyclohexanone with nitric acid.
R. Noyori et al., Chem. Commun., 1977-1986 (2003), discloses an oxidative system which employs a tungstate, hydrogen peroxide and a quartenary ammonium phase-transfer catalyst to get efficient cleavage of an alkene.
C.-M. Che, et al., Chem. Asian J., 1, 453-458 (2006), discloses that Ruthenium complexes containing 1,4,7-trimethyl-1,4,7-triazacyclononane with hydrogen peroxide furnishes dicarboxylic acid from different alkenes.
J. W. de Boer et al., Dalton Transactions, 6283-6295 (2008) discloses that suberic acid can be formed from cis-1,2-cyclooctanedi-ol and hydrogen peroxide and a dinuclear Mn catalyst with 1,4,7-trimethyl-1,4,7-triazacyclononane; and that epoxidation and/or cis-dihydroxylation of alkenes can be performed using a dinuclear Mn catalyst with 1,4,7-trimethyl-1,4,7-triazacyclononane in the presence of either L-ascorbic acid or dehydroascorbic acid.
A. Berkessel and C. A. Sklorz, Tetrahedron Letters, 40, 7965-7968 (1999) describe the use of a combination of a Mn-salt, 1,4,7-trimethyl-1,4,7-triazacyclononane, ascorbic acid and/or sodium ascorbate as catalyst system for the epoxidation of alkenes and the oxidation of primary and secondary alcohols.